174 Essential Operations Engineer Interview Questions You Must Master

This article gathers a comprehensive set of 174 interview questions commonly asked of operations (DevOps/Sysadmin) engineers. The questions span a wide range of topics, including the definition of operations, server management, networking, Linux commands, load balancing, storage RAID configurations, middleware, security, monitoring, and troubleshooting techniques.

What is operations? What is game operations?

In daily work, operations staff often need to interact with product staff; what does the product staff do?

If you are given three hundred servers, how would you manage them?

Briefly describe the working principles and characteristics of RAID0, RAID1, and RAID5.

What are the differences between LVS, Nginx, and HAProxy? How would you choose among them in practice?

What are the differences between Squid, Varnish, and Nginx? How would you choose among them?

What are the differences between Tomcat and Resin? How would you choose?

What is middleware? What is JDK?

Explain the meaning of Tomcat ports 8005, 8009, and 8080.

What is a CDN?

What is gray‑scale (canary) release for a website?

Describe the DNS domain name resolution process.

What is RabbitMQ?

Explain the working principle of Keepalived.

Describe the operation process of the three LVS modes.

How does InnoDB locate lock issues, and how can MySQL reduce master‑slave replication lag?

How to reset the MySQL root password?

Advantages and disadvantages of LVS, Nginx, and HAProxy.

What is middleware? What is JDK?

How to monitor and display real‑time TCP traffic on port 80; provide the complete command.

How to troubleshoot a server that fails to boot, step by step.

How to handle Linux system viruses.

If a virus file keeps recreating after deletion, how to resolve it?

Explain the TCP/IP seven‑layer model.

How to list the top ten IPs by page request count from Nginx access logs.

How to use tcpdump to monitor port 80 and identify the highest traffic source.

Write a script to determine which IPs in the 192.168.1.0/24 network are online (pingable).

Given Apache logs stored under /app/logs, how to retain only the most recent 7 days of logs?

General Linux optimization suggestions.

Extract the IP address of eth0 using cut (alternatively awk or sed).

Explain the function of a SecureCRT shortcut command.

Schedule a nightly backup of /var/www/html to /data with timestamped archives.

List the commonly used Nginx modules and their purposes.

Enumerate web server load‑balancing architectures you are familiar with.

How to view HTTP concurrent request count and TCP connection states.

Use tcpdump to sniff port 80 traffic and identify the top source.

Write a script to ping all hosts in 192.168.1.0/24 and report those that respond.

Provide a solution or command to keep only the latest 7 days of Apache access logs.

How to optimize a Linux system (high‑level suggestions).

Generate a random 32‑bit password in the shell.

Count the top 5 IPs with the most accesses in Apache access.log.

How to view the contents of a binary file.

In ps aux, what do VSZ and RSS represent?

How to detect and repair /dev/hda5.

Linux boot sequence overview.

Difference between symbolic links and hard links.

How to save the current disk partition table.

How to copy, paste, delete lines, and perform search/replace in a text file.

Manual installation of GRUB.

These questions are intended to help candidates prepare for operations engineer interviews by testing their knowledge of system administration, networking, performance tuning, and related technologies.